Three Bridges, properly known as Windmill Bridge, is a three-level crossing of bridges near Hanwell in west London, United Kingdom. Designed by Isambard Kingdom Brunel, the bridges are a clever arrangement allowing the routes of the Grand Junction Canal, Great Western and Brentford Railway, and Windmill Lane to cross each other: road above canal above railway. This allowed the railway to be in a deep cutting so it wasn't visible from Osterley Park. Work began in 1856, and was completed in 1859. The project was Brunel's last to be finished before he died on 15 September 1859.